检索结果-南通市图书馆

Polyoxometalates-derived nanostructures for electrocatalysis application

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2024年第5期43卷 1845-1866页

作者： Chao-Yue Sun Wen Li Kai Wang Wei-Jia Zhou Hai-Qing Wang institute for Advanced Interdisciplinary research(iAIR) College of Chemistry and Chemical EngineeringUniversity of JinanJinan250022China Shandong electrical Engineering and equipment Group Intelligent Electric co. Ltd.Jinan 250022China

The co.version of intermittent renewable electrical energy to chemical energy is of great importance which can not only mitigate current energy and environmental crisis but also co.tribute to the ongoing carbon neutrality national *** is serving as a low-carbon co.version technology that enables green and efficient energy co.version mainly through hydrogen evolution reaction(HER),carbon dioxide reduction reaction(co.(2)RR),and nitrogen reduction reaction(NRR).The co.e of electrocatalysis is the design and co.struction of low-co.t high-activity and high-stability electrocatalyst to drive reaction thermodynamics and *** employment of polyoxometalates(POMs)as platforms or precursors to co.struct different types of electrocatalysts has been widely ***,we systematically summarized the recent advances in POM-derived nanostructures for electrocatalysis *** strategies for precursor design and electrocatalyst synthesis were briefly *** morphology co.trol,phase co.trol,co.posite modulation,and heterostructure engineering in POM-derived nanostructures were presented in *** structure–activity relationship of POM-derived nanostructures is fully discussed for HER co.(2)RR,and NRR ***,the current challenges and future outlooks of POM-derived nanostructures are summarized to provide insights toward high-efficiency electrocatalysts for energy co.version technologies.

关键词： Microforming Cylindrical co.pression Size effects Grain orientation Inhomogeneous deformation

Multi-physical fields distribution in billet during helical electromagnetic stirring:A numerical simulation research

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第1期21卷 51-59页

作者： Dong Pan Qing-tao Guo Kai-lun Zhang Fu-zhi Yu Yu-ying Li Yu-bao Xiao State Key Laboratory of Metal Materials for Marine equipment and Application Anshan 114009LiaoningChina Ansteel Beijing research institute co. Ltd.Beijing 102200China

Electromagnetic stirring is one of the widely applied techniques to modify the quality of casting *** from co.ventional rotate stirring,the helical stirring is more professional in assisting multi-dimensional flow of molten metal and eliminating solidification *** this study,the single-winding helical stirring(SWHS)was introduced,offering advantages such as smaller volume and lower electromagnetic shielding co.pared to traditional helical stirring *** a co.prehensive numerical simulation,the stirring parameters of SWHS were adjusted to yoke inclination angle of 43°and frequency of 12 *** higher electromagnetic force and flow velocity in drawing direction,as well as the lower temperature gradient induced by the SWHS,are positive factors for homogeneous solidification of *** experimental results on Al-8%Si alloy and 0.4%C-1.1%Mn steel demonstrate that co.pared to rotate stirring,the SWHS process can induce better billet quality and is more effective in accelerating the equiaxed expansion and reducing element *** SWHS process can enhance the equiaxed ratio of the billet by 58.3%and reduce segregation degree of carbon element by 10.97%.co.sequently,SWHS holds great promise as a potential approach for improving the quality of co.tinuous casting billets.

关键词： billet electromagnetic stirring helical solidification element segregation numerical simulation

The effect of friction block hole co.figurations on the brake tribological performance of high-speed trains

在线全文

学校读者我要写书评

暂无评论

Friction 2024年第10期12卷 2241-2258页

作者： Yuanke WU Wei CHEN Youguang ZHU Zaiyu XIANG Honghua QIAN Jiliang MO Zhongrong ZHOU Tribology research institute School of Mechanical EngineeringSouthwest Jiaotong UniversityChengdu 610031China China Railway Engineering equipment Group co. Ltd.Zhengzhou 450016China

Three triangular friction block co.figurations are co.monly employed in high-speed train brake systems,namely,unperforated,perforated co.figuration with one circular hole,and perforated with three circular *** this study,we adopted these friction block types to investigate the effect of perforated friction block co.figurations on the brake performance of high-speed trains based on a self-developed brake test *** results indicate the significant impact of the number of the holes on the wear behavior,temperature distribution,and vibration characteristics of the brake *** friction surface of the unperforated block is co.ered by wear debris,while the perforated blocks produce less wear ***,the one-hole block exhibits a more uniform temperature distribution and better vibration behavior than that with three *** friction brake is a dynamic process,during which separation and attachment between the pad and disc alternatively occur,and the perforated structure on the friction block can both trap and expel the wear debris.

关键词： high-speed train block brake performance wear debris flow

Evaluation method for electromagnetic interference co.plexity of high voltage switch based on feature extraction and GCC-GRU network

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High Voltage 2024年第3期9卷 749-761页

作者： Wenchao Lu Jiandong Duan Lin Cheng Jiangping Lu Jiaxin Tao Jianning Yin School of electrical Engineering Xi'an University of TechnologyXi'anChina Power research institute of State Grid Shaanxi Electric Power co. LtdXi'anChina

When some new-type sensors are subjected electromagnetic interference(EMI),the traditional standard can no longer serve as the guidance for their EMI ***,it is necessary to evaluate the co.plexity of the new sensing equipment's suffering from electromagnetic interference.A hybrid method of feature extraction and co.plexity evaluation of Electromagnetic Interference signals based on generalised co.rentropy criterion(GCC)is ***,a variational mode deco.position al-gorithm for adaptive extraction of deco.posed signals is co.structed using GCC,and Generalised S-transform is used for processing and ***,acco.ding to the time-frequency space model,a new quantitative evaluation criterion interference factor is proposed,which overco.es the shortco.ings of the traditional qualitative classification and the inability to solve the cross classification of ***,the Gated Recurrent Unit is introduced,and the GCC-GRU evaluation model with GCC as the loss function is *** authors co.duct EMI tests and measured signal eval-uation with Medium Voltage and High Voltage switches,and the results show that the method proposed is co.rect and effective.

关键词： co.plexity criterion network

Multi-scale modeling for prediction of mechanical performance in brazed GH99 thin-walled structure

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第7期37卷 550-563页

作者： Yazhou LIU Shengpeng HU Yanyu SONG Wei FU Xiaoguo SONG Ning GUO Weimin LONG State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Shandong institute of Shipbuilding Technology Weihai 264209China China Machinery Intelligent equipment Innovation research institute(Ningbo)co. Ltd.Ningbo 315700China

Superalloy thin-walled structures are achieved mainly by brazing,but the deformation process of brazed joints is non-uniform,making it a challenging research *** paper reco.ds a thorough investigation of the effect of brazing parameters on the microstructure of joints and its mechanical properties,which mainly inquires into the deformation and fracture mechanisms in the shearing process of GH99/BNi-5a/GH99 *** macrosco.ic-microsco.ic deformation mechanism of the brazing interface during shearing was studied by Crystal Plasticity(CP)and Molecular Dynamics(MD)on the basis of the optimal brazing *** experimental results show that the brazing interface is mainly formed by(Ni,Cr,co.(s,s)and possesses a shear strength of approximately 546 *** shearing fracture of the brazed joint occurs along the brazing seam,displaying the characteristics of intergranular *** simulations show that dislocations disassociate and transform into fine twinning with increased *** simulated the shear deformation process of the brazed *** multiscale simulation results are co.sistent with the experimental *** mechanical properties of thin-walled materials for brazing are predicted using MD and CP methods.

关键词： Multi-scale modeling Brazing Shear mechanisms Crystal plasticity GH99 superalloy

co.mand filtered integrated estimation guidance and co.trol for strapdown missiles with circular field of view

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第5期35卷 211-221页

作者： Wei Wang Jiaqi Liu Shiyao Lin Baokui Geng Zhongjiao Shi School of Aerospace Engineering Beijing Institute of TechnologyBeijing 10081China China research and Development Academy of Machinery equipment Beijing 100089China Northwest Industries Group co. Ltd.Xi'an 710043China

In this paper,an integrated estimation guidance and co.trol(IEGC)system is designed based on the co.mand filtered backstepping approach for circular field-of-view(FOV)strapdown *** threedimensional integrated estimation guidance and co.trol nonlinear model with limited actuator deflection angle is established co.sidering the seeker's FOV *** boundary time-varying integral barrier Lyapunov function(IBLF)is employed in backstepping design to co.strain the body line-of-sight(BLOS)in IEGC system to fit a circular ***,the nonlinear adaptive co.troller is designed to estimate the changing aerodynamic *** generalized extended state observer(GESO)is designed to estimate the acceleration of the maneuvering targets and the unmatched time-varying disturbances for improving tracking ***,the co.mand filters are used to solve the"differential expansion"problem during the backstepping *** Lyapunov theory is used to prove the stability of the overall closed-loop IEGC ***,the simulation results validate the integrated system's effectiveness,achieving high accuracy strikes against maneuvering targets.

关键词： Integrated estimation guidance and co.trol Circular field-of-view Time-varying integral barrier Lyapunov function co.mand filtered backstepping co.trol Nonlinear adaptive co.trol Extended state observer

Neural Network Robust co.trol Based on co.puted Torque for Lower Limb Exoskeleton

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第2期37卷 83-99页

作者： Yibo Han Hongtao Ma Yapeng Wang Di Shi Yanggang Feng Xianzhong Li Yanjun Shi Xilun Ding Wuxiang Zhang School of Mechanical Engineering and Automation Beihang UniversityBeijing 100191China Beihang Goer(WeiFang)Intelligent Robot co. Ltd.Beihang UniversityWeifangChina research Center of Satellite Technology Harbin Institute of TechnologyHarbinChina Beijing Xinfeng Aerospace equipment co. LtdBeijingChina

The lower limb exoskeletons are used to assist wearers in various scenarios such as medical and industrial *** modeling errors of the exoskeleton in different application scenarios pose challenges to the robustness and stability of its co.trol *** Radial Basis Function(RBF)neural network is used widely to co.pensate for modeling *** order to solve the problem that the current RBF neural network co.trollers cannot guarantee the asymptotic stability,a neural network robust co.trol algorithm based on co.puted torque method is proposed in this paper,focusing on trajectory *** innovatively inco.porates the robust adaptive term while introducing the RBF neural network term,improving the co.pensation ability for modeling *** stability of the algorithm is proved by Lyapunov method,and the effectiveness of the robust adaptive term is verified by the *** wearing the exoskeleton under different walking speeds and scenarios were carried out,and the results show that the absolute value of tracking errors of the hip and knee joints of the exoskeleton are co.sistently less than 1.5°and 2.5°,*** proposed co.trol algorithm effectively co.pensates for modeling errors and exhibits high robustness.

关键词： Lower limb exoskeleton Model co.pensation RBF neural network co.puted torque method

An analysis of TinyML@ICCAD for implementing AI on low-power microprocessor

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第4期67卷 343-344页

作者： Guoqing LI Jingwei ZHANG Meng ZHANG Tuo LI Tinghuan CHEN Jun YANG Shandong Yunhai Guochuang Cloud co.puting equipment Industry Innovation co. Ltd. School of Integrated Circuits Southeast University Shandong Inspur Artificial Intelligence research institute co. Ltd. School of Science and Engineering The Chinese University of Hong Kong

Tiny machine learning(ML) is an important application area of artificial intelligence(AI), which focuses on deploying AI on small hardware platforms with co.strained resources [1, 2]. The high-level TinyML co.tests at high-level co.ferences promote the development of TinyML areas, such as DAC-SDC [3] and TinyML@ICCAD [4].

关键词：

Effect of heat treatment on co.rosion behaviors of Mg-6Gd-3Y-0.5Zr alloy

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

China Foundry 2024年第5期21卷 599-612页

作者： Fei Wang Bin-guo Fu Yu-feng Wang Tian-shun Dong Guo-lu Li Jin-hai Liu Hebei Key Laboratory of New Functional Materials School of Materials Science and EngineeringHebei University of TechnologyTianjin 300401China Tianjin institute of Aerospace Mechanical and electrical equipment Tianjin 300301China Tianjin Aerospace Long March Technology and equipment co. Ltd.Tianjin 300462China

The microstructures and co.rosion behaviors of as-cast,T4-treated,and T6-treated Mg-6Gd-3Y-0.5Zr alloys were systematically investigated by SEM,TEM,immersion test,and electrochemical co.rosion *** results show that the microstructure of the as-cast alloy is co.posed ofα-Mg and Mg_(24)(Gd,Y)_(5)eutectic phase,and in T4-treated alloy,Mg_(24)(Gd,Y)_(5)phase dissolves into theα-Mg matrix,leading to an increase in the(Y,Gd)H_(2)*** T6 treatment,nanoscale Mg_(24)(Gd,Y)_(5)phase dispersedly precipitates from theα-Mg matrix,and exhibits a specific orientation relationship with theα-Mg:(332)Mg_((24)(Gd,Y)_(5))//(1011)_(α-Mg),[136]Mg_((24)(Gd,Y)_(5))//[1210]_(α-Mg).The co.rosion resistance of the Mg-6Gd-3Y-0.5Zr alloys can be ranked in the following order:T6-treated alloy exhibits the highest co.rosion resistance,followed by the T4-treated alloy,and finally,the as-cast *** co.rosion products of the alloys are all co.posed of MgO,Mg(OH)_(2),Gd_(2)O_(3),Y_(2)O_(3),and MgCl_(2).The co.rosion behavior of Mg-6Gd-3Y-0.5Zr alloy is closely related to the precipitated *** establishing the relationship between co.rosion rate,hydrogen evolution rate,and co.rosion potential,it is further demonstrated that during the micro galvanic co.rosion process,the co.rse Mg_(24)(Gd,Y)_(5)phase in the as-cast alloy undergoes extensive dissolution,and(Y,Gd)H_(2)phase promotes the dissolution of theα-Mg matrix in the T4-treated alloy,intensifying the hydrogen evolution *** T6-treated alloy,with dispersive precipitation of nanoscale Mg_(24)(Gd,Y)_(5)phase,exhibits better co.rosion resistance performance.

关键词： Mg-6Gd-3Y-0.5Zr alloy heat treatment microstructure precipitated phase co.rosion resistance